I am very happy with them, They have a relatively balanced sound with a slight emphasis on bass which is tight and punchy.

Bass - The bass on these headphones is tight and punchy (not loose and flabby like the ATH-M50 which was always a bother for me). It is slightly emphasised but not offensively so, kick drums have a nice snap to them.

Mids - Their mids is nicely weighted with a solid enough presence to give guitars, drums and vocals plenty of texture without being harsh like the HD280. I personally find the ATH-M50 lacking in mids and find they make music sound a bit weak and thin.

Treble - They Have nice detailed treble that is pretty much where is should be but could be a little stronger on portable devices, With an amp (doesn't need to be huge) the treble comes through alot better. They are better in the treble department than the HD280 but not quite as good as the ATH-M50 although the ATH-M50 has a bit too much treble for me, I find it overbears the rest of the mix on those cans.

Comfort - They are very comfortable and beat both the HD280 and ATH-M50 hands down.

They come with a nice travel case and have a detatchable cable both of which are very welcome additions to the overall package.

My only real gripe is that the cups dont swivel vertically so when you take them off your head to talk to someone you can't flip the cup so the speaker is facing away from you instead of choking your neck.